Hyperuricemia is a condition of reduced uric acid excretion or excessive uric acid production due to environmental (lifestyle) or genetic factors, and leads to excess uric acid in the blood. Although hyperuricemia may lack subjective symptoms, it causes serious complications such as gout, renal dysfunction, urolithiasis, and arteriosclerosis. Acute arthritis with severe pain appears as a major symptom in gout, a representative complication of hyperuricemia. Gout was once called “the regal disease” and had been a “luxury disease” of those in the ranks that frequently consumed a lot of meat, fish, alcohol, and such; however, recently, it has been increasing yearly due to changes in the diet. The current population of gout patients in Japan is 300,000 to 400,000 people, and the population of hyperuricemia patients is estimated to be 6,000,000; thus, prevention and treatment of hyperuricemia is drawing increasing attention.
Prevention and treatment of hyperuricemia is carried out by controlling the uric acid level in blood through diet therapy, exercise therapy, pharmaceuticals, and combinations thereof. In particular, limiting caloric intake is one of the most frequently selected methods for preventing and treating hyperuricemia, but maintaining strict calorie restriction is not always easy. As a method for improving such circumstances, methods for lowering the serum uric acid level by orally ingesting microorganisms such as lactic acid bacteria and yeast that decompose purines (for example as pharmaceuticals or dietary products), and decomposing purines ingested from meals in the intestine to decrease their absorption into the body have been suggested. (Patent Document 1 and Non-patent Document 1). Lactic acid bacteria have been traditionally used as foods and pharmaceuticals, and since they are highly safe to the human body, consumption of lactic acid bacteria can be an effective method for preventing/treating hyperuricemia with little concern for side effects. Furthermore, as described above, the first choice of methods for preventing and treating hyperuricemia is diet therapy, and by ingesting lactic acid bacteria that allow control of uric acid levels as food, it may become a novel and very realistic, effective method for preventing and/or treating hyperuricemia. Although the lactic acid bacteria reported in the above-mentioned documents, Lactobacillus fermentum and Lactobacillus pentosus, are capable of decomposing purines, they have gas-producing ability and are not necessarily suitable bacterial species in terms of application as dietary products and pharmaceuticals.
[Patent Document 1] WO 2004/112809
[Non-patent Document 1] Homepage of the Japan Society for Bioscience, Biotechnology, and Agrochemistry (JSBBA), Annual Meeting of JSBBA Lecture and Presentation Database (which can be found on the World Wide Web at jsbba.bioweb.ne.jp/jsbba_db/index.html) “JSBBA 2004.03.30 general lecture, Ikenaga, T., Kumemura, M. et al.: Effects of lactic acid bacteria on the blood uric acid levels of dietary hyperuricemia model rats”